Rivet-type plastic fasteners are widely used as they are easy to install, perform well under shear and tensile loading, are serviceable, and can be used throughout a range of panel thicknesses. This type of fastener typically consists of a pin portion that is inserted into a body portion, the body portion being received in a hole formed through a substrate. In driving the pin portion into the body portion, the pin portion will capture a panel or other object between a head thereof and the body portion of the fastener. Typically, both panels are retained under the body head.
One disadvantage of a rivet-type fastener is that the effort required to drive the pin portion into the body portion is extremely dependent on the thickness of the panel in which the body portion is received and/or on the size of the hole within which the body portion is received. Small changes in the hole size or panel thickness can have a disproportionately large effect on the effort required to install the part. This relationship is particularly significant in light of safety-driven ergonomic requirements that mandate reduced installation forces for this type of fastener that can be as low as ten (10) pounds of force. Note that ergonomic requirements can vary from application to application. Accordingly, there is a recognized need to provide a rivet-type fastener that can accommodate variance in the size of the hole and thickness of panel into which it is installed. In addition to satisfying safety and ergonomic requirements, a fastener according to the present invention may be used in a greater number of disparate settings, thereby requiring fewer fasteners of differing size or style in a given assembly.